Sounds like he'll have to invest in a chamber reamer, use lots of oil, and give it a few very gentle turns in the tight chambers.
It's easy DIY.
After a minor cutting like this, I use 0000 steel wool to burnish and remove tool marks.
Reamers can be rented from 4drentals.com, or it might actually be cheaper to buy it, use it, then resell on eBay for very little loss.
Brownell's shows .44 Mag cylinder reamers in stock, which will work perfectly for this application. He doesn't need to lengthen the chamber (maybe a few thou clearance?) so this would work.
This problem is more common in S&W .22s but it happened in larger calibers, too.
The factory reamer must have been worn down to just undersized.
If he absolutely strikes out, I probably have a reamer I'd loan.

__________________
Chris
SWCA #2243 SWHF #292